Wireless service providers typically design their wireless networks to comprise a number of partially-overlapping wireless coverage areas. A radio access network (RAN) may allocate resources from these wireless coverage areas to wireless communication devices (WCDs) so that these WCDs can communicate using the resources. The resources may include, for example, frequencies, code division multiple access (CDMA) codes, time division multiple access (TDMA) timeslots, and so on.
Over time, a wireless service provider may incrementally deploy new media codecs. Some new media codecs may be of a higher quality than older media codecs. However, not all WCDs using the wireless service provider's network may support the new media codecs.